Display panel

ABSTRACT

The display panel comprises first and second layers of communicating gas-filled display cells. The first layer includes a first plate having grooves, with first electrodes seated in the grooves, and second flat strip electrodes supported by the plate so that the first and second electrodes and the gas in the slots between them form a first layer of cells. The second layer includes a second plate having cell apertures seated on the second electrodes, with third electrodes in the grooves of the second plate or on the top surface of the plate where an apertured plate is used, so that the second and third electrodes and the gas-filled space between them comprise the second layer of cells. Typically, in operation of the display panel, the second electrodes are connected in groups, and each group is connected to a source of operating potential. Various arrangements are described for connecting the second electrodes in such groups.

Unite States Patent [191 Caras [4 1 Feb. 25, 1975 DISPLAY PANEL [75] Inventor: Bernard Caras, Princeton, NJ.

[73] Assignee: Burroughs Corporation, Detroit,

Mich.

[22] Filed: July 2, 1973 [21] Appl. No.: 375,762

[52] US. Cl 313/188, 313/318, 339/18 C [51] Int. Cl. H0 1j 61/36 [58] Field of Search 313/201, 234, 188, 318,

313/220; 315/169 TV; 339/18 R, 18 C [56] References Cited UNITED STATES PATENTS 2,920,231 l/l960 Beurrier 315/169 TV 3,683,222 8/1972 Caras 313/220 X 3,739,218 6/1973 Maloney 313/188 Primary ExaminerAlfred E. Smith Assistant ExaminerWm. H. Punter Attorney, Agent, or FirmPaul W. Fish; Edward G. Fiorito; Robert A. Green [57] ABSTRACT The display panel comprises first and second layers of communicating gas-filled display cells. The first layer includes a first plate having grooves, with first electrodes seated in the grooves, and second flat stripelectrodes supported by the plate so that the first and second electrodes and the gas in the slots between them form a first layer of cells. The second layer includes a second plate having cell apertures seated on the second electrodes, with third electrodes in the grooves of the second plate or on the top surface of the plate where an apertured plate is used, so that the second and third electrodes and the gas-filled space between them comprise the second layer of cells.

Typically, in operation of the display panel, the second electrodes are connected in groups, and each group is connected to a source of operating potential. Various arrangements are described for connecting the second electrodes in such groups.

24 Claims, 11 Drawing Figures *{BFEBPSms I PATENI SHEET 1 0f 5 3 868.526

Fig.1

PRIOR ART PATENIEDFEB25 1915 3,868,526

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200 70B 700 70A 708 70c DISPLAY PANEL BACKGROUND OF THE INVENTION In display panels of the type described above, known as SELF-SCAN panels, the second electrodes are connected in groups. At the present time, no convenient mass production method is known for simply, quickly, and inexpensively connecting together the proper cathode electrodes in their proper groups.

The present invention solves this problem.

SUMMARY OF THE INVENTION Briefly, a display panel embodying the invention includes a base plate which carries a first array of electrodes and a face plate which carries the usual third array of electrodes, with an array of second electrodes disposed therebetween. Means are provided to connect the second electrodes in groups and to make electrical connection to the groups.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective exploded view of a display panel useful in practicing the invention;

FIG. 2 is a sectional view, taken along lines 22 in FIG. 1, but showing the display panel assembled;

FIG. 3 is a sectional view, along lines 3-3 in FIG. 1, showing the panel assembled;

FIG. 4 is a plan view of the display panel of FIG. 1 illustrating one embodiment of the invention;

FIG. 5 is a side elevational view of a portion of the panel of FIG. 4;

FIG. 6 shows a modification of the embodiment of FIG. 5;

FIG. 7 is a sectional view of a portion of a panel showing a modification of the invention;

FIG. 8 is a sectional view of a portion of a display panel showing a modification of FIG. 7;

FIG. 9 is a side elevational view of a portion of a panel showing a modification of the invention;

FIG. 10 is a side elevational view of a panel showing a modification of the invention of FIG. 9; and

FIG. 11 is a side elevational view of a portion of a panel showing still another modification of the inventron.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, a display panel 10 embodying the invention includes a first insulating base plate of glass, ceramic, or the like, having a top surface 40, a bottom surface 50, and a plurality of parallel slots or channels 30 formed in the top surface 40 thereof. The number of slots is determined by the number and size of the characters to be displayed in the panel, as will be clear to those skilled in the art.

First electrodes 60, generally operated as scanning anodes, are seated at the bases of the slots 30. Electrodes 60 may be wires, flat strips of metal, or they may be plated or evaporated or otherwise formed in the slots.

The panel also includes second electrodes 70, generally operated as scanning cathodcs, seated on or in the top surface 40 of the first plate 20 parallel to each other and at an angle. preferably 90, to the first electrodes 60. The electrodes 70 are flat metal strips. The region at which each second electrode 70 crosses a first electrode 60 defines a scanning gas cell 90, and these cells are arrayed in rows and columns. Each cathode strip electrode is provided with a series of apertures 100, each of which overlays a scanning cell so that communication can take place from each cell 90 through electrode 70 to other elements disposed above the electrodes 70 (to be described). It is noted that each cathode 70 forms, and is thus aligned with, a column of scanning cells.

A second insulating plate having a plurality of apertures or cells arrayed in rows and columns is seated on the electrodes 70, with each aperture or cell 120 vertically aligned with a scanning cell 90. The plate 110 may be of glass, ceramic, or the like.

Third electrodes 130, generally operated as display anodes, are disposed in any suitable manner between the apertured plate 110 and the panel face plate 150. The electrodes may be seated on the upper surface of the apertured plate 110, or they may be embedded either in slots in plate 110 or in slots in the face plate 150. The electrodes 130 are preferably wires, and they are oriented parallel to, and aligned with, the first electrodes 60, and each is aligned with a row of display cells 120 in the plate 110 and thus with a row of scanning cells.

In panel 10, the plates 20, 110, and are sealed together at their edges by means of a glass frit or the like to form a seal 170, shown in FIGS. 2 and 3. For convenience in making this seal, top plate 150 and bottom plate 20 are usually made somewhat larger than center plate 110, although such an arrangement is not essential.

Panel 10 also includes an ionizable gas such as argon, neon, or the like, and preferably a Penning mixture of such gases, and including a small quantity of mercury, to minimize cathode sputtering. The gas is provided at a suitable pressure for the intended purpose. The gas may be introduced by means of a tubulation (not shown) suitably secured to the panel, or it may be introduced in any other suitable manner.

According to the invention and referring to FIG. 4, the base plate 20 is shown enlarged and provided with a plurality of parallel slots 200 outboard of the panel seal and along the upper and lower edges thereof. The slots 200 are disposed generally transverse to the longitudinal axes of the cathode strips 70 so that the ends of these strips extend toward the slots. The end of each cathode is bent at about a 90 angle to the main body of the cathode and is conductively secured in one of the slots 200, and, if the cathodes are to be connected in three phases or three groups, the end of every third cathode is disposed in the same slot in any suitable manner. Thus, each cathode 70A has its end inserted in slot 200A, each cathode 708 has its end inserted in slot 200B, and each cathode 70C has its end inserted in slot 200C.

As to the method of securing the cathode ends in the slots, for example, a free end may be inserted (FIG. 5), or the end may be crimped into the slot (FIG. 6). The desired conductivity is achieved by inserting a conductive frit 210 into each slot in intimate engatement with the end of each cathode. A conductive frit typically comprises an intimate mixture of an insulating material such as glass or a plastic, and particles of a metal such as copper or the like. Such materials are well known in the art. To improve the conductivity, a wire 220 may also be inserted in each slot. This wire can also be used to provide external circuit contact to each group of cathodes.

Both ends of cathodes 70 may be bussed as illustrated in FIG. 4, or only a single end of each may be so bussed. As illustrated in FIG. 7, the cathode-slot assembly shown in FIGS. 4 to 6 may be disposed inside the panel,

rather than outside. In this arrangement, conductive plastics would be avoided, and glass frits would be used for securing the cathodes in place. In addition, slots 200 might be formed in face plate 150, rather than in base plate FIG. 8.

In another arrangement illustrated in FIG. 9, a plurality of spaced-apart insulating strips 230, of glass or plastic, carrying metal strips 240 are disposed adjacent to an edge of the base plate 20 of the panel 10, and the cathodes 70 of the same phase are disposed in contact with the same metal-insulating strip combination and secured thereto by layer 250 of a conductive cement. To avoid possible shorting between adjacent cathodes, the metal strips 240 and layers 250 of conductive cement are not as wide as the plastic strips 230, as shown in FIGS. 9 to 11. Electrical connection may be made to each layer of conductive cement at the ends thereof by means of suitable terminals (not shown).

Each layer of conductive cement tends to secure together the layers or strips between which it is positioned so that all of the layers or strips become secured together as a unitary assembly. If desired, in addition, the entire assembly of strips and electrodes may be potted in a suitable insulating medium to form a unitary assembly.

In a modification of the invention illustrated in FIG. 10, an auxiliary insulating spacer strip 260 is disposed between the panel and the first strip to space the bussed cathode assembly from the base plate 20 of the panel.

In a modification of the invention illustrated in FIG. 11, the insulating busing strips are spaced from the edge of the panel and are disposed horizontally. The cathode ends may be assembled with the insulating strips which have been coated with conductive cement and may be clamped together while heat is applied to secure the parts together in the desired relationship.

What is claimed is:

I. A display panel comprising a plurality of insulating plates, a first array of first electrodes and a second array of second electrodes, said second electrodes being positioned at an angle to said first electrodes,

means connecting a plurality of said second electrodes in a plurality of groups so that a single source of potential can be connected to all electrodes in a group at the same time,

said means comprising an assembly of a plurality of strips of insulating material, each strip carrying a strip of metal and having all of the electrodes of a group secured to said strip of metal by means of a conductive cement.

2. The panel defined in claim 1 wherein said conductive cement comprises a mixture of metallic particles and powdered glass particles.

3. The panel defined in claim 1 wherein said strips and said electrodes are disposed horizontally and are parallel to the surface of said panel.

4. The panel defined in claim 1 wherein the parts of said assembly are secured together by said conductive cement to form a unitary assembly.

5. The"panel defined in claim 4 wherein-said assembly is disposed parallel to a side edge of said panel, with the ends of the electrodes carried thereby being at a angle to the main bodies thereof.

6. The panel defined in claim 5 and including an insulating spacer disposed between a side edge of said panel and said assembly to space said assembly from said panel.

7. A display panel comprising a base plate and a face plate sealed together to form an envelope,

an array of first electrodes and an array of second electrodes disposed within said envelope to form a plurality of operating elements,

a plurality of parallel slots in a surface of one of said plates,

selected ones of said electrodes being arrayed in groups, with portions of the electrodes of each group being conductively secured in one of said slots.

8. The panel defined in claim 7 wherein said slots are formed in the top surface of said base plate.

9. The panel defined in claim 7 wherein said slots are inside said envelope.

10. The panel defined in claim 7 wherein said slots are outside said envelope.

11. The panel defined in claim 7 wherein said slots are inside said envelope.

12. The panel defined in claim 7 wherein said slots are outside said envelope.

13. The panel defined in claim 7 wherein said portions of said electrodes are the ends thereof.

14. The panel defined in claim 7 wherein said electrodes are secured in said slots by means of a conductive cement.

15. The panel defined in claim 14 and including a metal rod disposed in each of said slots to insure a conductive connection between each of the electrodes of a group with conductive cement therein.

16. A display panel comprising a first insulating plate having a top surface, a bottom surface and side edges, and a plurality of parallel grooves in said top surface,

a first electrode seated in each of said grooves,.

a plurality of second parallel electrodes spaced from said first electrodes and oriented at an angle to said first electrodes so that each second electrode crosses a plurality of first electrodes,

each crossing of a first electrode and a second electrode spaced therefrom defining a gas volume which comprises a gas cell,

a second plate having top and bottom surfaces and positioned above and in sandwich relation with said first plate and having a plurality of apertures arrayed in rows and columns, each aperture being aligned with a crossing of a second electrode and a first electrode,

third electrodes positioned on the top surface of said second plate, each aligned with a group of said apertures whereby a portion of each third electrode is aligned with a portion of a second electrode and a portion of a first electrode at each said aperture,

a top glass viewing plate covering said third electrodes, said first plate, second plate, and viewing plate being sealed together with an ionizable gas included inside said panel and in said cells, and

means connecting said second electrodes in groups so that a single source of potential can be connected to all of the second electrodes of a group at the same time,

said means comprising an assembly of a plurality of 5 strips of insulating material, each strip carrying a strip of metal and having all of the electrodes of a group secured to said strip of metal by means of a conductive cement.

17. The panel defined in claim 16 wherein the parts of said assembly are secured together by said conductive cement to form a unitary assembly.

18. The panel defined in claim 16 wherein said strips and said electrodes are disposed horizontally and are parallel to the surface of said panel.

19. The panel defined in claim 16 wherein said assembly is disposed parallel to a side edge of said base plate, with the ends of the electrodes carried thereby being at a 90 angle to the main bodies thereof.

20. The panel defined in claim 19 and including an insulating spacer disposed between a side edge of said panel and said assembly to space said assembly from said panel.

21. A display panel comprising an insulating base plate having a top surface and a bottom surface and a plurality of parallel grooves in said top surface,

a first electrode seated in each of said grooves,

a plurality of second parallel electrodes spaced from said first electrodes and oriented at an angle to said first electrodes so that each second electrode crosses a plurality of first electrodes,

each crossing of a first electrode and a second electrode spaced therefrom defining a gas volum which comprises a first gas cell,

a center plate disposed adjacent to said second electrodes and having a plurality of apertures arrayed in rows and columns, each aperture being aligned with one of said first cells, each aperture comprising a second gas cell,

a plurality of parallel third electrodes spaced from said second electrodes by said center plate and oriented at an angle to said second electrodes, each crossing ofa third electrode and a second electrode being at a second cell,

a face plate having a viewing window positioned adjacent to said third electrodes, said base plate, said center plate and said face plate being sealed together to form a gas-tight envelope filled with an ionizable gas, and

a plurality of parallel slots in a surface of said base plate or said face plate,

said second electrodes being arrayed in groups, with the ends of the electrodes of each group being conductively secured in one of said slots.

22. The panel defined in claim 21 wherein said slots are formed in the top surface of said base plate.

23. The panel defined in claim 21 wherein said electrodes are secured in said slots by means of a conductive cement.

24. The panel defined in claim 23 and including a metal rod disposed in each of said slots to insure a conductive connection between each of the electrodes of a group with conductive cement therein. 

1. A display panel comprising a plurality of insulating plates, a first array of first electrodes and a second array of second electrodes, said second electrodes being positioned at an angle to said first electrodes, means connecting a plurality of said second electrodes in a plurality of groups so that a single source of potential can be connected to all electrodes in a group at the same time, said means comprising an assembly of a plurality of strips of insulating material, each strip carrying a strip of metal and having all of the electrodes of a group secured to said strip of metal by means of a conductive cement.
 2. The panel defined in claim 1 wherein said conductive cement comprises a mixture of metallic particles and powdered glass particles.
 3. The panel defined in claim 1 wherein said strips and said electrodes are disposed horizontally and are parallel to the surface of said panel.
 4. The panel defined in claim 1 wherein the parts of said assembly are secured together by said conductive cement to form a unitary assembly.
 5. The panel defined in claim 4 wherein said assembly is disposed parallel to a side edge of said panel, with the ends of the electrodes carried thereby being at a 90* angle to the main bodies thereof.
 6. The panel defined in claim 5 and including an insulating spacer disposed between a side edge of said panel and said assembly to space said assembly from said panel.
 7. A display panel comprising a base plate and a face plate sealed together to form an envelope, an array of first electrodes and an array of second electrodes disposed within said envelope to form a plurality of operating elements, a plurality of parallel slots in a surface of one of said plates, selected ones of said electrodes being arrayed in groups, with portions of the electrodes of each group being conductively secured in One of said slots.
 8. The panel defined in claim 7 wherein said slots are formed in the top surface of said base plate.
 9. The panel defined in claim 7 wherein said slots are inside said envelope.
 10. The panel defined in claim 7 wherein said slots are outside said envelope.
 11. The panel defined in claim 7 wherein said slots are inside said envelope.
 12. The panel defined in claim 7 wherein said slots are outside said envelope.
 13. The panel defined in claim 7 wherein said portions of said electrodes are the ends thereof.
 14. The panel defined in claim 7 wherein said electrodes are secured in said slots by means of a conductive cement.
 15. The panel defined in claim 14 and including a metal rod disposed in each of said slots to insure a conductive connection between each of the electrodes of a group with conductive cement therein.
 16. A display panel comprising a first insulating plate having a top surface, a bottom surface and side edges, and a plurality of parallel grooves in said top surface, a first electrode seated in each of said grooves, a plurality of second parallel electrodes spaced from said first electrodes and oriented at an angle to said first electrodes so that each second electrode crosses a plurality of first electrodes, each crossing of a first electrode and a second electrode spaced therefrom defining a gas volume which comprises a gas cell, a second plate having top and bottom surfaces and positioned above and in sandwich relation with said first plate and having a plurality of apertures arrayed in rows and columns, each aperture being aligned with a crossing of a second electrode and a first electrode, third electrodes positioned on the top surface of said second plate, each aligned with a group of said apertures whereby a portion of each third electrode is aligned with a portion of a second electrode and a portion of a first electrode at each said aperture, a top glass viewing plate covering said third electrodes, said first plate, second plate, and viewing plate being sealed together with an ionizable gas included inside said panel and in said cells, and means connecting said second electrodes in groups so that a single source of potential can be connected to all of the second electrodes of a group at the same time, said means comprising an assembly of a plurality of strips of insulating material, each strip carrying a strip of metal and having all of the electrodes of a group secured to said strip of metal by means of a conductive cement.
 17. The panel defined in claim 16 wherein the parts of said assembly are secured together by said conductive cement to form a unitary assembly.
 18. The panel defined in claim 16 wherein said strips and said electrodes are disposed horizontally and are parallel to the surface of said panel.
 19. The panel defined in claim 16 wherein said assembly is disposed parallel to a side edge of said base plate, with the ends of the electrodes carried thereby being at a 90* angle to the main bodies thereof.
 20. The panel defined in claim 19 and including an insulating spacer disposed between a side edge of said panel and said assembly to space said assembly from said panel.
 21. A display panel comprising an insulating base plate having a top surface and a bottom surface and a plurality of parallel grooves in said top surface, a first electrode seated in each of said grooves, a plurality of second parallel electrodes spaced from said first electrodes and oriented at an angle to said first electrodes so that each second electrode crosses a plurality of first electrodes, each crossing of a first electrode and a second electrode spaced therefrom defining a gas volume which comprises a first gas cell, a center plate disposed adjacent to said second electrodes and having a plurality of apertures arrayed in rows and columns, each aperture being aligned with one of said first cells, each aperture comprising a second gas cell, a plurality of parallel third electrodes spaced from said second electrodes by said center plate and oriented at an angle to said second electrodes, each crossing of a third electrode and a second electrode being at a second cell, a face plate having a viewing window positioned adjacent to said third electrodes, said base plate, said center plate and said face plate being sealed together to form a gas-tight envelope filled with an ionizable gas, and a plurality of parallel slots in a surface of said base plate or said face plate, said second electrodes being arrayed in groups, with the ends of the electrodes of each group being conductively secured in one of said slots.
 22. The panel defined in claim 21 wherein said slots are formed in the top surface of said base plate.
 23. The panel defined in claim 21 wherein said electrodes are secured in said slots by means of a conductive cement.
 24. The panel defined in claim 23 and including a metal rod disposed in each of said slots to insure a conductive connection between each of the electrodes of a group with conductive cement therein. 